<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var str = "122323";
    console.log("字符串str为 :"+str);
    console.log("字符串str的长度为 :"+str.length);
</script>　　
</body>
</html>